Alleged sexual abusers not caught due to lost data: AFP

The AFP says several large investigations have not been solved because it could not access metadata.

In one, the AFP received a number of referrals in relation to Australian internet users allegedly involved in the sexual abuse of children and the production, dissemination and possession of child abuse material.

But more than a third of all possible offenders in a child-exploitation image-sharing network cannot be traced because their internet data was not recorded or retained by the service provider.

In another investigation, the IP address of a mastermind behind a money-laundering syndicate targeting an Australian bank could not be identified because the data was not retained by the carrier.

The AFP says about $80,000 of share investments were sold off from a number of accounts after scammers illegally obtained details of bank accounts that were linked to an online share trader.

The money from the illegal share trades was then transferred into a number of false accounts operated by criminals.

Six people were charged but the AFP says the mastermind escaped and was never tracked down.

Pooled metadata could be 'hacked or leaked'

Jon Lawrence from Electronic Frontiers Australia says the widespread use of smartphones and tablets means the information obtained through metadata could lead to elaborate profiling of individuals.

"The sort of information that's generated here, particularly when looked at in aggregate ... can generate a very, very specific profile on certain people very quickly," he said.

"For example, if you're looking at Twitter communications, the metadata, the information about when and who and where associated with a tweet, is much bigger than the tweet itself."

He says it could also pose a security threat if the information falls into the wrong hands.

"Just simply capturing all this data in one place is risky in the sense that it's open to misuse, it's open to being hacked or leaked," he said.

Greens Senator Scott Ludlam says Australians should be concerned about the amount of information already available to authorities and private companies.

"The policing agencies and the intelligence agencies need to take some responsibility," he said.

"If it's okay to obtain a search warrant to listen in on your phone call, it should be okay to obtain a search warrant to spy on your location and your whole social network.

"Metadata allows for incredibly invasive, real-time snooping of innocent Australians and I don't think it should be available to anybody who wants it unless there's a warrant."

A spokesman for Attorney-General George Brandis says it is too early to comment on possible changes to surveillance laws and his Department is waiting on recommendations from the Senate Committee, which are due in June 2014.

More than 25 countries in Europe have signed up to the Data Retention Directive, requiring companies to store metadata between six months and two years.

In the last financial year, the AFP says it has made about 58,000 requests for metadata from telecommunication companies, about two-thirds of which were to identify the IP addresses of possible criminals.